Condensation Guides

Condensation forms when warm, moisture-laden air contacts a cold surface. Windows are the coldest surfaces in most UK homes, making them the first place condensation appears. Light condensation on single-glazed windows in winter is common. Heavy condensation on double-glazed windows, or condensation that persists all day, signals excess indoor humidity or inadequate ventilation.

The solution combines reducing moisture sources—lidding pans, using extractor fans, drying clothes outdoors—with improving ventilation and upgrading to better-insulated glazing. Persistent condensation on window frames, sills, or surrounding walls creates conditions for mould growth within 48 hours. UK Building Regulations Part F sets minimum ventilation rates to prevent condensation and maintain indoor air quality.

Featured Guide

How to Stop Condensation on Windows

Why condensation forms on windows, when it signals a problem, and practical solutions that work. UK Building Regs and ventilation requirements explained.

All Condensation Guides

Condensation Outside Windows

Why condensation forms on the outside of windows and whether it's a problem.

Prevent Condensation in Winter

Winter condensation causes and practical solutions for UK homes.